Chill plate for use in molding tappet heads



Sept. 10, 1929. A. B. SCHALL 1,727,555

CHILL PLATE FOR USE IN MOLDING TAPPET HEADS Filed March 9, 1928 ATTORNEYPatented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

ALLEN B. SOHALL, OF SAGINAW, MICHIGAN, ASSIGNOR TO WILCOIC-RICH CORPORA-TION, 013 DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

CHILL PLATE FOR USE IN MOLDING TAPPET HnADs.

Application filed March 9, 1928. Serial No. 260,362.

This invention relates to foundry molds and pertains particularly tochill plates. The inventive novelty is found in the construction of theface of the chill plate, whereby the objects of my invention areattained.

The prime object is to so construct the face of the chill plate that itwill act to prevent eddying or swirling of the molten metal upon theface of the plate when pouring a tappet head casting or other similarlight thin piece of work that requires to be chilled evenly throughoutits area both as regards its internal metal structure and the uniformityof depth'to which the chilling and hardening l5 effect extends into thebody of the metal.

Cast iron tappets formed with chilled glass hard faces are in commonuse. They are usually cast in multiple mold flasks and the chill isproduced by making one face of the flask out of a plate of heavy metalthat serves as a chill plate common to all of the individual molds ofthe flask.

Various means have heretofore been provided, with the object ofproducing uniform depth of chill in a casting such as a tappet head thathas a flattened mushroom face combined with a central hub or boss. Suchchill plates give commercially good results except under certainconditions of moisture, mold temperature, etc., when a serious practi-'cal difliculty develops, namely, swirling of the molten metal when itstrikes the chill plate, resulting in an imperfect surface on theworking face of the chilled casting. This imperfection takes the form ofcreases or stream lines of various shapes, but usually spiral, thatextend over the entire area of the working face of the tappet head, orover only part of it. These stream lines produce uneven depth of chill,and since they must be ground away until they entirely disappear theyincrease the work of grinding, and What is more important, they requireso great depth of grinding over the entire face of the tappet head thatin some places the chilled iron is practically ground away, or at leastseriously weakened.

My invention, as above stated, has for its prime object. the eliminatingof the eddying movement of'the molten metal, the securing of uniformdepth of chill and the production of a Working face on the tappetcasting that can be ground away to an even depth, leaving an eventhickness of chilled metal to act as the working surface of the tappethead.

With the foregoing and certain other obects in View, which will appearlater in the specification, my invention comprises the devices describedand claimed and the equivalents thereof.

In the drawings Fig. 1 is a part sectional perspective view of a chillplate embodying my improvement, the grooves greatly enlarged forpurposes of description.

Fig. 2 is an end view of a tappet head molded in the manner shown inFig. 1. 4

Fig. 3 is a diagrammatic face View of a multiple mold chill plateindicating various arrangements of grooves.

Fig. 4 is a sectional detail showing grooves of various suitable crosssectional shapes.

Figs. 5 and 6 are face views of tappet head castings with' modifiedarrangements of grooves therein.

Fig. 7 is a sectional finished.

Fig. 8 is a face view of a tappet head casting before being machined.

As is clearly shown in the drawings the sand mold and chill plate areemployed in their usual relationship, the tappet casting being poured inthe ordinary manner as indicated in Fig. 1.

I form'the working with grooves 1, which may be of any desired crosssectional shape, as indicated in Fig. 4. These grooves may extend inrows lengthwise the chilled plate, as shown in Fig. 3, where a singlerow of grooves l is illustrated. I have indicated only two rows oftappet mold locations in Fig. 3, for purpose of illustration, but itwill be understood that four such rows are intended to be used in theparticular chill plate illustrated, giving room for thirty-two castingsat each pouring. i

- I have shown a number of different general schemes or arrangements ofgrooves, all of which are satisfactory in practice. In Figs. 1 and 2 and8 the grooves are parallel and extend straight across the diameter ofthe castview of a tappet head face of the chill' plate ing face. In Fig.5 they are part circular, being formed by facing off the chill plate andturning its grooves in a lathe. In Fig. 6 the grooves are arranged toradiate from the 5 center of the tappet head 2 to the edges.

. In each case, however, the grooves extend across the diameter of thetappet head and beyond, so that when the metal is poured it fills thegrooves 1, which instantly check any 10 tendency of the hot metal toswirl or rotate, thereby preventing eddies or creases in the faces ofthe finished casting.

Moreover the grooves, W ere they project beyond the edge of the casting,are closed by the sand of which the mold is made, and this rammed sandforms a filter-like gas vent, through which the gases formed in moldingseep along the grooves and have their pressure relieved. The completedcasting has a uniform depth of chill and no surface irregularitiescaused by swirling action of the molten metal. When the face of thecasting is ground 0E as in Fig. 7, there is left a chilled working faceof extreme density and hardness and of'uniform depth and thickness.

Having thus described my invention, what I claim and desire to secure byLetters Patent is: 4

.30 In a mold for the production of cast metal articles having chilledfaces, a chill plate provided with means for preventing swirling ofmolten metal when poured into said mold, while attaining in the finishedarticle a normal predetermined depth of surface chill, said meanscomprising a chill late whose working face is formed with fine y dividedgrooves, the depth of said grooves being suflicient to prevent eddyingof the molten metal, and less i 40 than the predetermined depth ofthechilled area.

In testimony whereof, I aifix my signature.

ALLEN B. SGHALL.

